A cowl top panel is provided in an upper area closer to an engine compartment at the border between the engine compartment and the passenger compartment in a front vehicle body for an automobile. The cowl top panel is provided at the lower end of the front shield. Generally, a wiper unit is mounted on the cowl top panel.
For example, as shown in FIG. 5, the front vehicle body structure disclosed in Patent Document 1 has a first cowl 51 that is provided between left and right front pillars 50 and a second cowl 53 that is provided between left and right apron upper members 52 at the front side of the first cowl 51. The second cowl 53 has a U-shaped cross section, opens upwardly, and extends linearly. Left and right end portions of the second cowl 53 are connected to an upper surface of the left and right apron upper members 52 and top surfaces of left and right suspension towers 54 with bolts. The second cowl 53 increases rigidity of the front vehicle body portion and suppresses vibration and noise caused in the front vehicle body portion due to the vibration of tires when the vehicle moves. Patent Document 1 has no disclosure whatsoever regarding a wiper unit.
A front vehicle body structure disclosed in Patent Document 2 has a cowl top rear 60 and a cowl top front 61 as shown in FIG. 6. The cowl top rear 60 is provided between left and right front pillars. The cowl top front 61 is provided between left and right apron upper members at the front side of the cowl top rear 60. A wiper support portion 62 is formed at either end portion of the cowl top rear 60. Bottom portions of the wiper support portion 62 are connected to top portions of the left and right suspension towers 63. A wiper unit of an overlap type (not shown) is mounted to the wiper support portions 62. That is, the wiper unit has a pair of pivot shafts that are arranged with a great distance therebetween and a pair of wiper blades that are rotated in opposite directions.
Generally, when a wiper unit is operated, great bending moment is repeatedly applied to the cowl top panel from the wiper unit. The bending moment is based on reaction force received by the wiper blade from a wiped surface and load that is applied to the wiper unit by inertia caused when a rotation direction of a wiper motor is switched and the wiper motor is stopped. Therefore, if the cowl top panel does not have enough bending rigidity with respect to the vehicle widthwise direction, the operation of the wiper unit is unstable. Accordingly, the wiping operation of the wiper may not be executed appropriately or abnormal noise may be caused. In the structure disclosed in Patent Document 2, since each of the two end portions of the cowl top rear 60 is fixed to each of the top portions of the suspension towers 63, the cowl top rear 60 is hardly deformed.
However, wiper units that are generally used are not overlap type that is used for the structure disclosed in Patent Document 2, but the tandem type. In the wiper unit of the tandem type, the pivot shafts of a pair of wiper blades are provided at a center portion with respect to the vehicle widthwise direction so as to be close to each other and the wiper blades are rotated in the same direction. It is difficult to arrange the wiper unit of the tandem type at two end portions of the cowl top rear 60 disclosed in Patent Document 2. Further, unlike the second cowl 53 disclosed in Patent Document 1, the cowl top 60 disclosed in Patent Document 2 is not formed to extend linearly along the vehicle widthwise direction. This hardly increases the rigidity of the front vehicle body portion.    Patent Document 1: Japanese Laid-Open Patent Publication No. 11-115811    Patent Document 2: Japanese Laid-Open Patent Publication No. 2004-330939